The invention relates to a robot with an at least partly externally located cable, particularly robot tool supply cables guided in a conduit and having a length reserve, particularly in the vicinity of the A3 axis of the robot.
The resulting distance changes between individual points of the robot must be taken into consideration particularly when guiding the supply cables, e.g. of robot tools.
In order to be able to carry out such distance changes without stressing the supply cables, the latter must have a length reserve. With externally guided supply cables the problem arises that in the robot arm working positions where the length reserve is not used, the supply cables can give rise to a relatively large interfering contour and as a result of the length reserve a bending or kinking of the supply cables can occur on stressing.
Therefore the problem of the invention is to so further develop a robot of the aforementioned type that with very simple components, the interfering contour caused by the supply cables can be kept as small as possible and that despite the supply cable length reserve a bending thereof is avoided.
According to the invention the set problem is solved in the case of a robot of the aforementioned type by a base part located on the robot and having elements for guiding the supply cables and with a leg pivotable against the latter, on which is located at least one of the elements for supply cable guidance. Through the base part passing through the supply cables in the area of their length reserve, the supply cables are closely guided on the outside of the robot parts, which leads to a reduce interfering contour and as a result of the increase guidance there is also a smaller supply cable bending risk. Through the arrangement of the supply cables on the base part, there is also a significant reduction to the sideways movement of said supply cables.
As a result of the leg pivotable against the base part and the provision of elements for guiding the cable both on the leg and on the base part, the cable guide can follow the stressed cable, so that the angles which arise between the guide elements significantly reduce the bending risk.
According to a preferred embodiment the base part has stops, which limit the pivotability of the leg in both pivoting directions and with which it is possible to ensure that the supply cables can only be displaced in a certain, limited range. The leg or arm is fundamentally freely movable in the limited area. Its position is determined by the conduit held by it and by its elasticity.
The leg can additionally be connected by a spring element to the base part, which keeps the leg in a given position in the unstressed state and from which it can only be moved by a stress acting counter to the spring tension.
According to an advantageous development on the base part is provided a ledge for fixing the individual supply cables, so that they are secured in the starting area of the length reserve and consequently there is no influencing of the cable guide in the section upstream of the length reserve.
Advantageously said ledge has individual bores in which are individually guided that supply cables and which can consequently also be individually fixed, so that mutual influencing of the supply cables is substantially avoided.
The supply cables are preferably movably guided on the guide on the leg of the base part. Thus, the supply cables remain mobile along the path predetermined by the guide elements and can follow the robot arm movements.
In a particularly favourable variant the supply cables are guided in a conduit, which prevents damage or twisting of the supply cables, the conduit being fixed to the base part and movably guided on the leg.
Advantageously the base part has further devices for fitting guide elements for the supply cables, with which it is possible in an optimum manner to guide to the robot parts excess lengths, i.e. with a minimum interfering contour.
According to a preferred embodiment the base part has a fixing element for connection to the robot arm, the letter being advantageously located on the motor screws of the A3 axis or shaft. The arrangement of the fixing element in the immediate area of the rotation axis of the robot arm, in the case of movements of the latter leads to a relative movement between the supply cable and the base part which, in proportion to the rotary movements of the robot are about the A3 axis of the robot ensures the bend-free guidance of the supply cable.
In a particularly simple and inexpensive construction the fixing element is a flange.